If you have a garden full of plants, you have to deal with nasty parasites in summer. This is how you get rid of the pests.
Due to the corona pandemic, many will be taking their vacation in the garden at home this year. In summer, however, more parasites spread there and eat their fill of the abundant flowering plants and vegetables. Garden expert Eliz Simon, author of "Take care of yourself: The great manual" (Riva Verlag), explains in an interview with the news agency spot on news what is important when it comes to gardening in midsummer and how pests can be eliminated in an environmentally friendly way.
Ms. Simon, which garden pests are particularly active in summer?
Eliz Simon: The six types of pests that are most common in the home garden and cause the most damage are: voles, snails, caterpillars (especially cabbage white caterpillars), cabbage fly larvae, whitefly and aphids. In midsummer, when the harvest season slowly begins, even larger animals in rural areas look forward to the richly laid table in the house garden. Hares and rabbits, sometimes even deer, rummage in cabbage and lettuce, blackbirds and starlings fall on cherry trees and berry bushes and can destroy entire harvests.
What damage do they do in the garden?
Simon: Voles throw tall and unsightly piles out of the earth. Vole heaps are generally taller than molehills. Through their passages in the ground, voles compact the earth, but above all they eat the roots of the most diverse plants (hardly any vegetable or garden shrub is safe from them) and thus cause the plants to wither.
Snails are probably the most widespread and also the most hated pests. Small and large nudibranchs hide under the soil during the day. At night they crawl out and fall on all plants growing close to the ground, such as lettuce, cabbage, cucumber, herbs and much more. It happens so quickly that the next day you can hardly see what you have planted the day before. It also often happens that sown plants cannot even sprout because the germs are already eaten in the early stages.
Who does not know the famous children's book "The Very Hungry Caterpillar" by Eric Carle. The caterpillars of the cabbage white butterfly are just that – gluttonous and endlessly voracious. They attack the cabbage plants especially in midsummer, when the herbaceous plants have a lot of leaf mass and the harvest is imminent. If you don't do anything about it, you can watch how your cabbage heads get fewer and fewer from day to day and ultimately consist of only a skeleton.
The larvae of the cabbage fly actually only attack cabbage (rarely also radishes and radishes). They eat their way into the plant through the root stem and plant attachment, causing it to wither. If you take the plant out of the ground, you can see that it has almost no roots.
The whitefly actually belongs to the aphid family. It is originally a tropical pest and has only appeared in Central Europe for a few decades. The whitefly lice and the aphids are not picky, they populate the leaves and stems of garden vegetables, but also flower bushes and small trees and shrubs. They suck out the plants and weaken them. Yellow, falling leaves and withered branches are the result. A black, sticky coating often forms on the leaves of the plant: the sooty fungus, which further weakens the plant.
Which plants are particularly susceptible to pests?
Simon: Pests especially like young, still very tender plants that they can easily chew with their tiny eating tools. Plants with smooth leaves are also more popular than, for example, zucchini or pumpkins, the leaves of which are covered with numerous tiny spines. Highly aromatic plants such as tomatoes, leeks or onions are usually spared from pests that love it tasteless.
How do you know that a plant is infected?
Simon: You can tell that a plant has been attacked by a pest first and foremost by the pest itself. Aphids occupy the plants close together and often form a real layer that is easy to see. Snails crawl out of the ground in droves when the weather is damp. The cabbage flies fly out of the herb in flocks like this when you touch it or douse it with a jet of water. Caterpillars are up to five centimeters long and easy to spot on the cabbage leaves, and the associated butterflies, the white cabbage white butterfly, flutter around the herbaceous plants. Infested plants wither, lose leaves, rot or die. In plants with lice infestation, the sooty fungus, a black film that can easily be rubbed off with your fingers, tends to form on the leaves.
Are there any environmentally friendly (household) remedies that can effectively remove the pests?
Simon: There are various environmentally friendly (household) remedies and preventive measures that can be used to combat pests. If you have pests in your garden, you don't have to despair. Pests are also not a sign of inability or poor gardening, but mostly the result of certain weather conditions. The presence or absence of beneficial organisms (hedgehogs, foxes, ladybugs, parasitic wasps, ear peas) also has an impact. But every gardener has that in their own hands. Anyone who has invested weeks and months in their beloved garden has a right to the harvest and does not have to be eaten away by voracious caterpillars or aphids.
Voles don't like bad smells. That's why you simply use the rake or a sharp jet of water to uncover various digging holes under the pile and put some grated garlic or a few tablespoons of sour milk into these holes. The voles are looking for another corner – guaranteed!
Snails don't like drought, which is why the snail problem has massively decreased in many regions due to the dry and hot summers. Admittedly – at the same time, there are fewer and fewer beneficial insects such as foxes and hedgehogs that the snails eat. If you have the opportunity, you can put ducks in your garden, two are completely sufficient. Running ducks love snails, they will absolutely clean up any garden! Snails, on the other hand, like lumpy, compacted, loamy soil on which they can crawl easily. You can spoil this preference for them by chopping the soil regularly and making it crumbly. You can also pick up, collect and then destroy all visible snails at the same time. In the case of bought-in young cucumber, lettuce or herbaceous plants, a hood made of translucent glass (for example an old jam jar) is recommended for the first four or five days, which protects the plant until it is larger, stronger and less susceptible.
Cabbage white caterpillars should be collected and taken to a remote location. Because cabbage whites are actually pretty, white butterflies. If the infestation is too strong, the leaves of the cabbage plants are sprayed on all sides with a homemade emulsion made from 30 percent rapeseed oil and 70 percent water. The caterpillars are covered with a film of oil and die.
The cabbage fly itself is not harmful, it is its larvae that eat their way into the stems and then into the plant itself. Fighting larvae infestation is therefore not possible; only prevention helps here. Cabbage plants heavily infested with larvae should be removed from the bed to protect the surrounding plants.
Lice infest plants especially when it is very dry (especially in spring), because lack of water thickens the sap and makes it more nutritious for the lice. The main thing that helps here: pour! If the infestation is severe, a stinging nettle brew is also effective. Put on gloves and put a large bunch of nettles in a bucket, fill it with water and then let it stand for a few days. If you spray your infested plants with this brew, the lice will disappear by themselves. A nettle brew is also a good fertilizer and strengthens your plants against various other diseases.
When can pests only be combated with chemicals?
Simon: Chemistry has no place in the home garden. There is one exception: iron sulfate. A biologically completely harmless remedy against snails is made from iron sulphate (which occurs in the soil itself). This remedy can be bought in stores. I recommend it on wet days – when you can no longer cope with the snail plague.
How can you prevent vermin in your own garden?
Simon: If you want to prevent, you have to strengthen your plant. In the home garden, this includes a humus-rich soil fertilized with compost and manure, different crop rotations (do not put the same plant in the same place year after year), plant stock made from nettles and horsetail and sufficient distance to the next plant so that the pests do not have too easy a game . You should also plant mixed cultures: onions or leeks, for example, keep the carrot fly away, and strongly smelling plants generally keep different types of pests away. Put insect hotels all over your yard to encourage insect life. For the cabbage fly, but also for the cabbage white butterfly, close-meshed, commercially available nets help preventively in the spring over the beds that have already been planted.